Windshield antenna system

ABSTRACT

An improved windshield antenna system is described in which a pair of laminated glass sheets forming the windshield contains a pair of antenna wires adhered to the laminating interlayer. The wires have free ends which extend out beyond a cutout portion formed in one of the glass sheets. The free ends of the wires are terminated to an attaching area of a conductive terminal which terminal is received in the cutout portion of the glass sheet. An electrical lead is also connected to the conductive terminal at the attaching area. A nonconductive tab is affixed to one surface of the glass sheet away from the cutout portion of the one glass sheet. The tab holds the electrical lead in a relatively stable position with respect to the attaching area of the conductive terminal at which the lead is terminated to the antenna wires. A potting compound overlies the region of the termination of the antenna wires and the electrical lead to the attaching area of the conductive terminal.

United States Patent [72] Inventors Richard T. Dickason Birmingham; JohnA. Richardson, Harper Woods, Mich. [21 Appl. No. 848,799 [22] Filed Aug.11, 1969 [451 Patented May 18, 1971 810,814 3/1959 GreatBritainABSTRACT: An improved windshield antenna system is described in which apair of laminated glass sheets forming the windshield contains a pair ofantenna wires adhered to the laminating interlayer. The wires have freeends which extend out beyond a cutout portion formed in one of the glasssheets. The free ends of the wires are terminated to an attaching areaof a conductive terminal which terminal is received in the eutoutportion of the glass sheet. An electrical lead is also connected to theconductive terminal at the attaching area. A nonconductive tab isaffixed to one surface of the glass sheet away from the cutout portionof the one glass sheet. The tab holds the electrical lead in arelatively stable position with respect to the attaching area of theconductive terminal at which the lead is terminated to the antennawires. A potting compound overlies the region of the termination of theantenna wires and the electrical lead to the attaching area of theconductive terminal.

Patentd 'a'y18,1911 T 3,579,243

ATTORNEYS wrNnsiiiistb ANTENNA SYSTEM BAC KGROU ND OF THE INVENTION Inthe recent past, windshield antenna systems have been introduced for usein conjunction with the radio receivers mounted within automotivevehicles. More particularly, the antenna for the radio is placed in theresinous interlayer which laminates together the sheets of safety glassutilized for forming the windshield of the vehicle. In general, theantenna system is formed by a pair of fine wires which are positionedfor a portion of their length in the central portion of the glass. Thewires extend from the base of the windshield upwardly to a point nearthe top of the windshield. The wires then extend outwardly along twodiverging legs to termination points near the top side edges of thewindshield.

The antenna wires, in order not to impair visibility through thewindshield and detract from the appearance of the vehicle, are formedfrom wire of a very fine diameter. Since the fine diameter wire is usedfor the antenna system, the manner in which the antenna wire isterminated to an electrical lead which may be connected to the radio isof great importance. The termination is important so that duringinstallation and utilization of the windshield antenna, substantialstress loads are not applied to the termination point of the wires.Since the wires are of such a fine diameter, any substantial stress loadapplied thereto would cause a rupture of the termination between thewires and the electrical lead and thus an interruption in the use of theantenna system.

The improved'antenna system of this invention is designed to eliminatetwo problems previously encountered in the termination of the very finediameter wires used in windshield antenna systems. More particularly,the windshield antenna system of this invention is designed in a firstimproved aspect to provide termination elements which will not moveduring the termination procedure to sever or to sheer the fine wiresforming the antenna. The windshield antenna system also provides in asecond improved aspect a connection between the electrical lead and thefine antenna wires which is so constructed that if external forces areapplied to the electrical lead, the forces are transmitted through thetermination elements to the glass sheets rather than to the junctionformed between the antenna wires and the electrical lead.

SUMMARY OF THE INVENTION This invention relates to an antenna windshieldsystem and, more particularly, to the manner in which an antennawindshield system is terminated so that the antenna might be connectedto the radio of an automobile vehicle.

In general, an antenna windshield system is formed from the followingelements: a first sheet of glass, a second sheet of glass having acutout portion overlying the first sheet of glass, an interlayer ofresinous material bonding the two sheets of glass together in anassembled condition, and at least a pair of antenna wires adhered to theinterlayer between the glass sheets. The antenna wires extend upwardlyin the central portion of the windshield and then outwardly alongdiverging leg portions which extend in opposed directions across the topof the windshield. The antenna wires, at their free ends in the centralportion of the windshield, are initially exposed for a portion of theirlength at the cutout portion of the second glass sheet.

In accordance with the structure of the windshield antenna system ofthis invention, a conductive terminal is formed to be receivable withinthe cutout portion of the second glass sheet. An electrical lead is alsoprovided which is insulated over a major portion of its length. The leadhas an exposed end. An attaching device is provided on the conductiveterminal for securing both the free ends of the antenna wires theretoand the exposed end of the electrical lead thereto. A nonconductive tabis affixed to a surface of the glass sheets. This tab holds an insulatedportion of the electrical lead in a relatively stable position withrespect to the exposed end of the electrical lead which is attached bythe attaching device on the conductive terminal to both the antennawires and the terminal. A sealant overlies the region of the pair ofglass sheets wherein the cutout portion is located in order to seal theconductive terminal, the antenna wires and the exposed end of theelectrical lead from the elements.

In greater detail, the conductive terminal is formed so as to have anextending portion which engages at least a small surface area of thecutout portion of the second glass sheet whereby an opening is leftbetween most of the terminal and the surface of the second glass sheetdefining the cutout portion thereof. The initially exposed portions ofthe antenna wires located at the cutout portion of the glass sheet passthrough this opening. During the assembly of the antenna system, anymovement of the conductive terminal will not cause a sheering of antennawires between the terminal and the surface of the cutout portion of thesecond glass sheet because of the presence of the opening in this area.

In still greater detail, the nonconductive tab is affixed to the surfaceof the first glass sheet away from the cutout portion of the secondglass sheet. This tab has a portion thereof defining a passagewayextending along the edge of the assembled glass sheets. An insulatedportion of the electrical lead is received in close confiningrelationship within the passageway. Since the passageway confines theinsulated electrical lead, any force applied to the unexposed end of theelectrical lead is transmitted through engagement of the insulatedportion of the lead and the passageway to the plastic tab and then tothe glass sheets to which the tab is affixed. In such a manner, theforce applied to the lead is not, in turn, applied to the connectionformed by the antenna wires, the attaching device and the exposed end ofthe electrical lead.

Thus, the structure of this invention eliminates two problems heretoforeencountered in fabrication of the antenna windshield system. The firstproblem solved is that the conductive terminal to which the antennawires are terminated cannot be moved against the antenna wires so as tocause a severing of the same between the terminal and the cutout surfaceof the second glass sheet. The second problem solved by the antennasystem of this invention is that any force applied to the electricallead connecting the antenna wires to the radio will be transmitted fromthe lead to the sheets of glass rather than to the termination of theantenna wires and the lead.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view showing theimproved portion of the windshield antenna system of this invention.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1 showingin greater detail the structure of FIG. 1.

FIG. 3 is an exploded, isometric view of the various elements utilizedin the formation of the windshield antenna system of this invention.

FIG. 4 is a diagrammatic view of a windshield having an antenna systemlocated therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT This invention relates to awindshield antenna system and, more particularly, to an improvedtermination for the fine antenna wires utilized in such a system. Thewindshield antenna system is shown in FIG. I and is generally designatedtherein by the numeral 10.

The following basic parts are utilized in the formation of thewindshield antenna system 10. A first glass sheet 12 and a second glasssheet 14 are laminated together by utilization of a resinous materialsuch as a polyvinyl butryl interlayer 16 in a normal laminatingoperation. The glass sheets are normally 0.l25 inch in thickness and theinterlayer is normally 0.030 inch in thickness. The second glass sheet114 has a cut out portion 18 formed therein for the purpose of exposingthe ends of a pair of fine antenna wires 20-20. These fine antennawires, for example, may have a diameter of approximately 0.0054- 0.0056inch and be formed of copper having a resistance of approximately 415ohms per 1,000 feet.

As may be best seen in FIG. 4, the antenna wires extend upwardly fromthe cutout portion 18 of the second glass sheet 14 to a point at whichthe ends thereof, laminated between the glass sheets 12 and 14, extendparallel to the base of the glass sheets. The length dimension of theantenna wires in the direction parallel to the base of the glass sheetsis one of the principal controlling factors in the receptioncharacteristics of the antenna. As indicated in FIG. 4, the outwardlyturned ends of the antenna wires 20-20 are generally laid in the portionof the windshield wherein the gradient band 22 (indicated by dashedlines at its lower end) is positioned. The gradient band is dark incolor and it reduces the amount of light energy which may pass throughthe upper portion of the windshield. Also, because the gradient band isthe darkest portion of the windshield, the extending legs of the antennaare not easily seen from either side of the windshield.

The antenna wires 20-20 are preferably adhered to the resinousinterlayer 16 in an initial process operation. Such adherance may beaccomplished by laying the antenna wircs out in a prescribed pattern onthe interlayer and thereafter ironing the wires to heat themsufficiently so that they become bonded to the interlayer. Thereafter,the interlayer containing the wires is placed between the first glasssheet 12 and the second glass sheet 14 and heat and pressure are appliedthereto so that the two glass sheets are laminated into a windshield.Prior to the lamination operation, the free ends of the antenna wireswhich extend out beyond the cutout portion 18 of the second glass sheet14 are bent up and laid over the second glass sheet so that they do.notbecome firmly adhered to the resinous material during the autoclavingstep of the laminating operation.

In accordance with the teachings of the invention, a conductive terminal24 (best seen in FIG. 3) is utilized in terminating the antenna wires 20so that the antenna wires may be connected to the radio of theautomobile vehicle. In greater detail, the preferred conductive terminal24 is formed from a brass plate, the plate thereafter having a coat oftin placed thereover. The terminal has a thickness of 0.015 inch and maybe bonded to the interlayer 16 during the autoclaving step of thelaminating operation. In such a case, the conductive terminal is held inproper position during the autoclaving operation by means of a clip sothat a secure bond is formed between the interlayer and the terminal.

In accordance with a feature of this invention, the conductive terminal24 has a pair of extending legs 26-26 (best seen in FIG. 3). Theextending legs engage opposite sides of the cutout portion 18 of thesecond glass sheet 14 whereby a space or opening 28 (FIG. 1) is createdbetween the terminal 24 and the facing surface of the cutout portion ofthe sheet. In such a manner, if the conductive terminal is moved orotherwise jarred during the assembly thereof, the sharp end or edge ofthe terminal will not come into contact with and thus sheer the fineantenna wires 20 against the surface of the cutout portion of the secondglass sheet. As may best be appreciated from FIG. 1, in an assembledcondition after autoclaving, the antenna wires would be underneath thesecond glass sheet 14 but the free ends thereof would emerge therefromand pass through the opening 28 between the glass sheet and theconductive terminal. In an alternate form, the conductive terminal 24may be formed with only a single extending leg which would be located inthe central portion of the terminal. This single leg would engage thecutout portion of the second glass sheet between the two antenna wiresleaving an opening on either side thereof.

The conductive terminal also has a small projecting portion 30 formedthereon (best seen in FIG. 3). The projecting portion 30 is locatedintermediate the extending legs 26 of the terminal. The projectingportion 30 extends initially, before the termination of the antennawires to the terminal, in a direction towards and beyond the exposededges of the glass sheets 12 and 14.

An electrical lead 32 is provided which is insulated over a majorportion of its length. The electrical lead has an exposed end 34 whichis pretinned and a connector end 36 which is utilized for connecting thelead 32 to the antenna input for the radio circuitry.

A nonconductive tab 38 is also provided and this tab may be formed froma material such as acrylonitrilebutadiene styrene copolymer, commonlyknown as ABS type plastic. The nonconductive tab has a double coatedpressure sensitive material 40, such as neoprene foam, placed on aportion thereof extending over a substantial area. The nonconductive tabalso has a front portion 42 which has a passageway 44 formedtherethrough. Adjacent and forming a continuation of the front portion42 of the tab is another flat portion 46 which extends along the lengthof the tab a distance approximately equal to the length of the frontportion. The front portion and the flat portion of the tab togetherdefine a rear surface 48 (seen in FIG. 2).

ASSEMBLY As previously mentioned, the first and second glass sheets 12and 14 are bonded together in a standard laminating operation utilizingthe resinous interlayer l6 therebetween. As also previously mentioned,the fine antenna wires 20 may be adhered to the interlayer 16 prior tothe laminating operation. In such a case, free ends of the antenna wires20 are bent out and over the second glass sheet at the cutout portion 18thereof. As also previously mentioned, the conductive terminal 24 may besecured to the resinous interlayer 16 during the autoclaving operationin the glass laminating procedure.

After autoclaving, the windshield is washed. Thereafter, the free endsof the fine antenna wires 20 are individually brought down and wrappedat least one turn around the projecting portion 30 of the terminal 24.This is best illustrated in FIG. 1 where the convergence of the twoantenna wires to the projecting portion 30 is shown. If the antenna wirehas some type of a polymetric or paint coating thereover, it isnecessary to sand the wires to expose the copper under the coating priorto wrapping the wire around the projecting portion of the terminal.

When the antenna wires have been wrapped about the projecting portion 30of the terminal 24, the exposed end 34 of the electrical lead 32 isplaced in a position on the conductive terminal 24 directly adjacent theprojecting portion 30 of the terminal. The projecting portion of theterminal is then folded up and over and clamped down upon the exposedend 34, as is best appreciated by viewing FIGS. 1 and 2. Solder is thenflowed over the connection so that an intimate electrical junction isformed between the antenna wires 20, the projecting portion of theconductive terminal 24 and the exposed end 34 of the lead 32.

The electrical lead 32 is preassembled to the nonconductive tab 38 priorto the termination of the exposed end 34 of the lead to the conductiveterminal 24 and the antenna wires 20. Once the termination operation hasbeen completed, the operator adheres the nonconductive tab 38 by meansof the pressure sensitive material 40 to the surface of the first glasssheet 12 on the side opposite the cutout portion 18 of the second glasssheet 14 (best seen in FIGS. 1 and 2). When this is done, the rearsurface 48 of the front portion 42 and the flat portion 46 of the tab 38engage the edge of the glass sheet 12. The tab thus fonns a barrier forblocking any direct physical contact with the junction.

As will best be understood by reference to FIG. 1, a portion of theelectrical lead 32 is doubled back upon itself in that the lead issecured to the terminal 24 and thereafter passes through the passageway44 of the front portion 42 of the tab 38. By forming the lead back uponitself and passing it through the closely encircling passageway, anyforce applied as a pulling force to the connector end 36 of the lead 32will be transmitted by means of the lead 32 to the walls of thepassageway 44 and from there to the tab 38 and the glass sheet 12 towhich it is adhered. The pulling force, therefore, is dissipated and isnot applied to the junction formed by the antenna wires 20, the exposedend 34 of the lead 32 and the projecting portion 30 of the terminal 24.This construction thus accomplishes a second feature of the improvedantenna windshield system of this invention.

A sealing compound 50, shown only in FIG. 2, is applied over thetermination point of the antenna wires and the exposed end of theelectrical lead in order to protect the junction formed therebetween.The sealing material or compound is flowed by any suitable means intothe space formed between the cutout portion 18 0f the second glass sheetI4 and the front portion and flat portion, respectively 42 and 46, ofthe tab 38. For example, a potting compound may be dispensed through apressurized nozzle arrangement to fill the space as aforedescribed. Asuitable potting compound may be formed from a material such as siliconerubber base adhesive. This type of sealing material dries fairly rapidlyand once it is dried, it forms a barrier which is impervious to moistureand other types of detrimental materials which could ruin the electricalcharacteristics of the antenna wire junction.

Thus, there has been described a preferred embodiment of a windshieldantenna system in which the antenna wires cannot be accidentally shearedby the terminal to which the wires are to be terminated. Also, theimproved windshield antenna system presents a system wherein any pullingforce applied to the electrical connector which connects the antenna tothe radio of the automobile vehicle is dissipated as a force applied tothe glass rather than to the antenna wire junction,

We claim:

1. In a windshield antenna system which includes a first sheet of glass,:1 second sheet of glass having a cutout portion overlying the firstsheet of glass, an interlayer of resinous material between the two glasssheets bonding the same together in an assembled condition, and at leasta pair of antenna wires adhered to the inner layer between the glasssheets, the antenna wires being initially exposed for a portion of theirlength at the cutout portion of the second glass sheet, the improvementcomprising:

a conductive terminal formed so as to engage at least a small portion ofthe cutout portion of the second glass sheet to leave an opening betweenmost of said terminal and the surface of the second glass sheet definingthe cutout portion thereof, the initially exposed portions of theantenna wires passing through said opening;

an electrical lead insulated over a major portion of its length andhaving an exposed end;

attaching means on said conductive terminal for securing both saidantenna wires thereto and said exposed end of said electrical leadthereto, said attaching means including (1) a small projecting portionformed on said terminal about which the exposed ends of the antennawires may be wrapped to terminate the same and which may be folded overon the exposed end of said insulated lead to clamp said lead betweensaid projecting portion and said terminal, and (2) electricallyconductive solder flowed over the area of said projecting portion onsaid terminal both to which the antenna wires are terminated and whichclamps the exposed end of said insulated lead; a nonconductive tabaffixed to the surface of the first glass sheet away from the secondglass sheet, said tab having a portion thereof defining an elongatedpassageway extending along the edge of the assembled glass sheets, saidinsulated portion of said electrical lead being received in saidpassageway whereby any force applied to the exposed end of saidelectrical lead is transmitted through engagement of the insulatedportion of sad lead and said passageway to said plastic tab and then tothe glass sheets and not to the connection formed by the antenna wires,said attaching means and said exposed end of said electrical lead; and

- sealing means overlying the region of the pair of glass sheets whereinthe cutout portion is located for sealing said conductive terminal, theantenna wires and said exposed end of said electrical lead to protectthe same.

2. The windshield antenna system as defined in claim I, wherein saidprojecting portion formed on said terminal extends initially beforetermination of the antenna wires and clamping of said lead in adirection towards and beyond the exposed edges of the glass sheets.

3. The windshield antenna system as defined in claim 2, wherein saidconductive terminal is formed generally in a crescent configuration toconform to the cutout shape of the second piece of glass, opposite endsof the terminal having extending legs which engage the cutout surface ofthe second glass sheet at the spaced points whereby said opening is leftbetween said terminal and the cutout portion of the second glass sheetfor passage of said antenna wires therethrough, and wherein saidprojecting portion of said terminal is positioned at a locationintermediate said extending legs.

4. The windshield antenna system as defined in claim 2, wherein saidconductive terminal is formed generally in a crescent configuration toconform to the cutout shape of the second piece of glass, the centralportion of said terminal having an extending leg which engages thecutout surface of the second glass sheet at a location between the twoantenna wires whereby an opening is left on either side of saidextending leg between said terminal and the cutout portion of the secondglass sheet for passage of said antenna wires therethrough, and whereinsaid projecting portion of said terminal is positioned in alignment withthe axis of said extending leg,

5. The windshield antenna system as defined in claim 4, wherein said tabis affixed to the surface of the first glass sheet away from the secondglass sheet by a binding material initially carried by said tab.

6. The windshield antenna system as defined in claim 5, wherein saidportion of said tab defining said passageway also defines a wall whichextends along another portion of the edges of the two glass sheets, saidwall and said portion of said tab defining said passageway providingprotection for said connection of the antenna wires from direct physicalcontact being made therewith when the edges of the glass sheets areengaged by an object.

7. The windshield antenna system as defined in claim 6, wherein said tabis formed from ABS plastic.

8. The windshield antenna system as defined in claim 7, wherein saidsealing means is a potting compound formed from a silicone rubber baseadhesive.

1. In a windshield antenna system which includes a first sheet of glass, a second sheet of glass having a cutout portion overlying the first sheet of glass, an interlayer of resinous material between the two glass sheets bonding the same together in an assembled condition, and at least a paIr of antenna wires adhered to the inner layer between the glass sheets, the antenna wires being initially exposed for a portion of their length at the cutout portion of the second glass sheet, the improvement comprising: a conductive terminal formed so as to engage at least a small portion of the cutout portion of the second glass sheet to leave an opening between most of said terminal and the surface of the second glass sheet defining the cutout portion thereof, the initially exposed portions of the antenna wires passing through said opening; an electrical lead insulated over a major portion of its length and having an exposed end; attaching means on said conductive terminal for securing both said antenna wires thereto and said exposed end of said electrical lead thereto, said attaching means including (1) a small projecting portion formed on said terminal about which the exposed ends of the antenna wires may be wrapped to terminate the same and which may be folded over on the exposed end of said insulated lead to clamp said lead between said projecting portion and said terminal, and (2) electrically conductive solder flowed over the area of said projecting portion on said terminal both to which the antenna wires are terminated and which clamps the exposed end of said insulated lead; a nonconductive tab affixed to the surface of the first glass sheet away from the second glass sheet, said tab having a portion thereof defining an elongated passageway extending along the edge of the assembled glass sheets, said insulated portion of said electrical lead being received in said passageway whereby any force applied to the exposed end of said electrical lead is transmitted through engagement of the insulated portion of sad lead and said passageway to said plastic tab and then to the glass sheets and not to the connection formed by the antenna wires, said attaching means and said exposed end of said electrical lead; and sealing means overlying the region of the pair of glass sheets wherein the cutout portion is located for sealing said conductive terminal, the antenna wires and said exposed end of said electrical lead to protect the same.
 2. The windshield antenna system as defined in claim 1, wherein said projecting portion formed on said terminal extends initially before termination of the antenna wires and clamping of said lead in a direction towards and beyond the exposed edges of the glass sheets.
 3. The windshield antenna system as defined in claim 2, wherein said conductive terminal is formed generally in a crescent configuration to conform to the cutout shape of the second piece of glass, opposite ends of the terminal having extending legs which engage the cutout surface of the second glass sheet at the spaced points whereby said opening is left between said terminal and the cutout portion of the second glass sheet for passage of said antenna wires therethrough, and wherein said projecting portion of said terminal is positioned at a location intermediate said extending legs.
 4. The windshield antenna system as defined in claim 2, wherein said conductive terminal is formed generally in a crescent configuration to conform to the cutout shape of the second piece of glass, the central portion of said terminal having an extending leg which engages the cutout surface of the second glass sheet at a location between the two antenna wires whereby an opening is left on either side of said extending leg between said terminal and the cutout portion of the second glass sheet for passage of said antenna wires therethrough, and wherein said projecting portion of said terminal is positioned in alignment with the axis of said extending leg.
 5. The windshield antenna system as defined in claim 4, wherein said tab is affixed to the surface of the first glass sheet away from the second glass sheet by a binding material initially carried by said tab.
 6. The windshield antenna system as defined in claim 5, wherein said portion of said tab defining Said passageway also defines a wall which extends along another portion of the edges of the two glass sheets, said wall and said portion of said tab defining said passageway providing protection for said connection of the antenna wires from direct physical contact being made therewith when the edges of the glass sheets are engaged by an object.
 7. The windshield antenna system as defined in claim 6, wherein said tab is formed from ABS plastic.
 8. The windshield antenna system as defined in claim 7, wherein said sealing means is a potting compound formed from a silicone rubber base adhesive. 